qemu: Pass qemuCaps to qemuDomainSaveImageOpen

Since qemuDomainDefPostParse callback requires qemuCaps, we need to make
sure it gets the capabilities stored in the domain's private data if the
domain is running. Passing NULL may cause QEMU capabilities probing to
be triggered in case QEMU binary changed in the meantime. When this
happens while a running domain object is locked, QMP event delivered to
the domain before QEMU capabilities probing finishes will deadlock the
event loop.

This patch fixes all paths leading to qemuDomainSaveImageOpen.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_driver.c

@@ -6805,6 +6805,7 @@ qemuDomainSaveImageUpdateDef(virQEMUDriverPtr driver,
 /**
  * qemuDomainSaveImageOpen:
  * @driver: qemu driver data
+ * @qemuCaps: pointer to qemuCaps if the domain is running or NULL
  * @path: path of the save image
  * @ret_def: returns domain definition created from the XML stored in the image
  * @ret_data: returns structure filled with data from the image header
@@ -6819,6 +6820,7 @@ qemuDomainSaveImageUpdateDef(virQEMUDriverPtr driver,
  */
 static int ATTRIBUTE_NONNULL(3) ATTRIBUTE_NONNULL(4)
 qemuDomainSaveImageOpen(virQEMUDriverPtr driver,
+                        virQEMUCapsPtr qemuCaps,
                         const char *path,
                         virDomainDefPtr *ret_def,
                         virQEMUSaveDataPtr *ret_data,
@@ -6943,7 +6945,7 @@ qemuDomainSaveImageOpen(virQEMUDriverPtr driver,
     }
 
     /* Create a domain from this XML */
-    if (!(def = virDomainDefParseString(data->xml, caps, driver->xmlopt, NULL,
+    if (!(def = virDomainDefParseString(data->xml, caps, driver->xmlopt, qemuCaps,
                                         VIR_DOMAIN_DEF_PARSE_INACTIVE |
                                         VIR_DOMAIN_DEF_PARSE_SKIP_VALIDATE)))
         goto error;
@@ -7126,7 +7128,7 @@ qemuDomainRestoreFlags(virConnectPtr conn,
 
     virNWFilterReadLockFilterUpdates();
 
-    fd = qemuDomainSaveImageOpen(driver, path, &def, &data,
+    fd = qemuDomainSaveImageOpen(driver, NULL, path, &def, &data,
                                  (flags & VIR_DOMAIN_SAVE_BYPASS_CACHE) != 0,
                                  &wrapperFd, false, false);
     if (fd < 0)
@@ -7223,7 +7225,7 @@ qemuDomainSaveImageGetXMLDesc(virConnectPtr conn, const char *path,
 
     virCheckFlags(VIR_DOMAIN_SAVE_IMAGE_XML_SECURE, NULL);
 
-    fd = qemuDomainSaveImageOpen(driver, path, &def, &data,
+    fd = qemuDomainSaveImageOpen(driver, NULL, path, &def, &data,
                                  false, NULL, false, false);
 
     if (fd < 0)
@@ -7261,7 +7263,7 @@ qemuDomainSaveImageDefineXML(virConnectPtr conn, const char *path,
     else if (flags & VIR_DOMAIN_SAVE_PAUSED)
         state = 0;
 
-    fd = qemuDomainSaveImageOpen(driver, path, &def, &data,
+    fd = qemuDomainSaveImageOpen(driver, NULL, path, &def, &data,
                                  false, NULL, true, false);
 
     if (fd < 0)
@@ -7345,7 +7347,7 @@ qemuDomainManagedSaveGetXMLDesc(virDomainPtr dom, unsigned int flags)
         goto cleanup;
     }
 
-    if ((fd = qemuDomainSaveImageOpen(driver, path, &def, &data,
+    if ((fd = qemuDomainSaveImageOpen(driver, priv->qemuCaps, path, &def, &data,
                                       false, NULL, false, false)) < 0)
         goto cleanup;
 
@@ -7412,7 +7414,7 @@ qemuDomainObjRestore(virConnectPtr conn,
     virQEMUSaveDataPtr data = NULL;
     virFileWrapperFdPtr wrapperFd = NULL;
 
-    fd = qemuDomainSaveImageOpen(driver, path, &def, &data,
+    fd = qemuDomainSaveImageOpen(driver, NULL, path, &def, &data,
                                  bypass_cache, &wrapperFd, false, true);
     if (fd < 0) {
         if (fd == -3)